The present invention relates to a pump, in particular a vane cell pump or a roller cell pump, the vane cell pump or roller cell pump having a double-stroke contour ring and a rotor in which vanes or rollers are radially displaceably mounted, having at least one, possibly two, side plates which laterally seal the rotary cell group, having a housing and a housing cover, the rotor being driven by a shaft and the shaft being supported in the housing and possibly in the cover.
The present invention relates in particular to a double-flow vane cell pump, this double-flow, double-stroke vane cell pump being able to shut off one pump section at higher rotational speeds if needed due to the separation into two pump sections, and the pumped quantity of this pump section being returnable into the suction line. This shut-off has the effect that the rotor and the stroke ring are no longer pressure-equalized in the radial direction since almost no pressure is built up in the shut off pump section. This results in a lateral force which acts on the rotor and the stroke ring. When operating pressures increase, this lateral force causes the stroke rings, supported on pins, to be pushed radially more strongly from their original position due to the deflection of the pins. Due to the shaft deflection, the rotor, supported on the shaft, is displaced from its original position in the opposite direction. These displacements have a substantial effect on the noise behavior of the pump.